Saturday, April 17, 2010

Today I will be posting for a third time on one of my favorite subjects, the IBM Model M Keyboard. First, I will talk about tips, then give some links with a description about what can be found on them.

How to open/unscrew a Model M?

The shell of the Model M is held together by four hex nut screws. Three are recessed. You need a nut driver to open it. The proper size is 7/32" and it should have a slim barrel. You can find the correct driver in a Sears.
The proper name of the product is Craftsman 7/32 in. Easy-To-Read Socket, 6 pt. Deep, 1/4 in. drive, model #45815.

If your Model M does not work reliably or at all, your PS/2 port may be to blame. The Model M is a device from the mid-to-late 80s, and the keyboard control board and LEDs inside the machine draw a lot more current than a throw-away, el-cheapo modern keyboard use. It requires 275mA, whereas a modern cheapo keyboard may only need 1/10 of that. Some PS/2 ports just cannot provide the current for a Model M to run reliably or at all. I have never encountered this particular problem myself, but according to the link below, it can be found in many motherboards.

There are two solutions to this problem, both are listed on this page: